<?php
//echo sqrt(9),"\n";//开平方
//echo cos(60*pi()/180),"\n";//余弦，参数的单位是弧度
//echo cos(deg2rad(60)),"\n";//度转化为弧度
//echo pow(3,2),"\n";//3的平方
//echo round(3.1415926,1),"\n";//保留1位小数
//echo round(3.1415926,3),"\n";//保留3位小数
echo "已知三角形的边角边，各数据间用逗号分隔开来\n";
echo "请输入三角形的边角边，各数据间用逗号分隔开来：\n";
$count=fscanf(STDIN,"%f ,%f ,%f ,%s",$a, $beta, $b, $others);
//echo "count=$count, a=$a, b=$b, beta=$beta, others=$others\n";
if($count>3){//用户输入的数据后边有多余的东西
    echo "输入的数据后边不要加多余的乱七八糟的东西~\n";
}else if ($count<3){
    echo "数据输入有误，请根据提示按格式输入数据~\n";
}else{
    $c=round(sqrt($a*$a+pow($b,2)-2*$a*$b*cos($beta*pi()/180)),2);
    echo "三角形对边的长度=$c\n";
}
